Transporting bulk quantities of heavy material from one location to another requires specialized equipment and packaging. Such bulk products include, among others, aluminum, brass, steel and plastic. These materials are often shipped in stacked flat sheets, bars or plates, or in large rolls. Bulk quantities of sheet aluminum, for example, are often shipped in large rolls that can be several feet wide, several feet high and weigh several thousands of pounds. These bulk materials, which are difficult to handle by themselves, must be packaged so that lifting equipment (such as a forklift) can have access to lift and transport the packaged payload quickly, easily, safely, and without damaging the payload material, as most bulk material packages will be handled several times between manufacture and end-use.
For example, after coming off of the manufacturing line in its final, ready-for-shipment form, the material is usually first moved to a staging or storage area. It is then typically moved to a shipping dock area, where is loaded onto a truck for shipment to the final destination, or to a long-haul carrier such as a train or plane. If to the latter, the packaged material will be handled several more times before reaching its end-use destination. Once there, the packaged material must be unloaded, placed in storage, and then moved yet again when actually used. Moreover, if not all of the material in one package is used at a single time, the package may be moved several more times to and from storage before all of the packaged material is used. Accordingly, it is not unusual for these heavy bulk payloads to be handled four, five, and even up to ten or more times before the material is completely used. Therefore, some means for allowing the packaged material to be easily moved must be provided.
The device most often used in the prior art for this purpose is the ubiquitous wooden pallet or skid, which consists of a wooden base to which are attached two or more wooden runners that extend the entire length of the base. The payload sits on the base and the runners provide space between the base and the ground (or other surface upon which the pallet or skid sits) so that the handling equipment, such as the tines of a forklift for example, can have access to get under the base to lift and move the packaged payload. These payloads are generally strapped to the pallet or skid using metal bands or other suitable means which are tightened prior to shipping. The pallet or skid and its strapped-on payload are then capable of being lifted and moved by overhead crane, fork lift trucks or other suitable device.
These wooden pallets are often custom-made to correspond to the exterior dimensions of the bulk material, and are made of rough-cut hardwood such as oak because of its beneficial combination of relative high strength, low weight and small cost, characteristics which are difficult to find in union. Any transportation pallet or skid must be strong to withstand the gross weight of the payload and the rigors associated with handling and transportation. Also, because almost all freight cost is based upon gross weight transported, the goal is always to add as little weight to the payload as possible. Therefore, low weight is also a design goal. Lastly, the preferred pallet or skid will cost as little to construct and maintain as possible.
As effective and efficient as these wooden pallets or skids have been, they do suffer from a number of deficiencies. First, with heavy bulk materials, the wooden devices are considered "one-way" shipping platforms because they are not reusable. Although oak is a "hard" wood and is therefore among the strongest and most durable woods available at a reasonable cost, the wooden devices and particularly the runners are subjected to substantial abuse during handling. Sometimes, the runners or base or both will be damaged by the handling equipment itself, as when the forklift driver miscalculates and runs the tines into the runners instead of the open space between them. Also, when the loaded pallet or skid is placed down, the forklift driver will often allow the load to descend at the maximum rate allowed by the equipment, and rarely is the driver concerned about whether the runners of the pallet or skid are perfectly parallel to the ground or truck bed. Therefore, one end or edge of one runner will hit the ground or truck bed first, with that one end or edge bearing all of the energy developed by the extremely heavy load descending at speed. Or the ground may be uneven such that one part of the runner will bear significantly more of the load impact. In either event, the runners tend to become rapidly damaged and disfigured, such that they cannot be reused. This not only raises the per-use cost of the wooden device, but also requires additional costs associated with storage of used pallets or skids pending dismantling and discard, and with the actual dismantling and discard. This is not only an unnecessary item of cost, but a nuisance as well.
Second, the wooden pallets or skids are subject to performance deficiencies. Because of the heavy loads which they must carry and the rigors of handling which they must endure, it is not unusual for them to become so damaged in transit that they must be repaired or replaced before reaching the end-user. This is particularly problematic because to replace the pallet or skid requires that the payload be removed from one and placed on another. The reason the pallet or skid was required in the first place, however, was because the payload itself was not easily moved, and not by the usual transportation means such as a standard forklift. Therefore, if the pallet or skid fails in transit, the payload itself must now be lifted and moved, often with tools ill-suited for the task. Not only is this difficult, time-consuming and inefficient, it can be dangerous, particularly if the appropriate equipment is not available in the field.
Third, the wooden devices are somewhat heavy and expensive, particularly when compared with the invention disclosed below. For example, a typical wooden pallet or skid made for a 5,000 pound payload of 4'.times.10' aluminum sheets requires approximately 56 board feet of lumber, and weighs about 215 pounds. The gross lumber costs are currently about $68, and are increasing as the cost of lumber has been steadily increasing. Assembly, dismantling and discard costs raise the per-use cost for a standard wooden pallet or skid to well over $100. As the wooden pallets or skids are often one-time-only use, that adds well over $100 to the net cost of each payload, which is passed along to the end-user, and ultimately to the end-user's customers, and so on.
Fourth, wooden pallets and skids use a natural resource--wood; and the used pallets and skids, or parts of them, may be burned or sent to landfill sites, adding to environmental pollution. Therefore, the use of wooden pallets and skids is not ecologically preferred.
Therefore, there exists a need for an improved skid or pallet for use with heavy bulk payloads that overcomes these problems associated with the prior art.